How to make a noun plural

With some exceptions, Spanish nouns tend to follow these rules to become plural:

Add s:

a)    If the noun ends in a vowel: la casa- las casas (house- houses); el libro- los libros (book- books); el café- los cafés (café- cafes)

b)    To most foreign nouns ending in a consonant: el chalet- los chalets; el jersey- los jerseys (jumper- jumpers).

Add es:

a)    If the noun ends in a consonant other than s: la flor- las flores (flower- flowers); la ciudad- las ciudades (city- cities).

b)   If it ends in a stressed vowel followed by s: el inglés- los ingleses (Englishman- Englishmen)

When es is added to make a noun plural, any accent on the last vowel of the singular disappears: el melocotón- los melocotones (peach- peaches);

But if the singular contains the combination of aí or aú, the accent is kept in the plural: el país- los países (country- countries); el baúl- los baúles (trunk- trunks).

When es is added to a noun ending in z, the z becomes a c in the plural: la cruz- las cruces (cross- crosses).

No change:

a)    If the noun ends in an unstressed vowel followed by s: la crisis- las crisis (crisis- crisis); el virus- los virus (virus- viruses)

b)   For some foreign nouns: el test- los test.

Irregular Plurals:

Some nouns change their stress in the plural:

El carácter- los caracteres (character- characters); el régimen- los regímens (regime- regimes); el/la joven- los jóvenes (young person, young people).